trail and triple clamps

[semi old guy]

i posted this in the suspension forum because it seems to be the most closely related topic. i'm looking for thoughts on if and why increasing the trail by going to less offset in the clamps (say 18mm vrs 20mm) improves the turning. this seems to be a trend. the thing is...increasing the trail should improve the stability also. if this is the case why don't the manufacturers do it. there would be no downside. KTM clearly sells reduced offset clamps to improve turning right? what are typical offsets that the other manufactures use?

 

[semi old guy]

sorry it seems i'm beating a dead horse. i just saw the previous discussion. anyway i'm thinking that the reason it improves turning has to do with how the tire patch behaves when you're in a turn and feeding input to the bars. the thing that doesn't make sense is it should improve stability also. i've had a few KTMs that were both poor turners and unstable. speaking of Tony Foale, he basically says stability is a function of trail and not rake.

 

[Shawn Mc]

Stability is a function of both rake and trail, I understand the relationship, but Im not smart enough to be able to explain it on paper.

 

[svi]

Increasing the trail does not help steering it does though improve stability. If you project a line through the centre of the steering axis to the ground then from the centre of the wheel to the ground, the distance between the two points is the trail, to see how trail works look at a shopping cart wheel the contact patch of the wheel is a relatively long way from the steering axis (lots of trail) so whichever way you push the cart the wheel follows, this is known as self aligning torque. Therefore when your riding along on your bike the wheel wants to go straight ahead all the time so the more trail you have the more effort is required to turn it.